1. Field of the Invention
The present invention relates generally to a method of manufacturing a semiconductor device and a semiconductor device using the same and, more particularly, to a method of manufacturing a semiconductor device and a semiconductor device using the same, which may improve productivity.
2. Description of the Related Art
Since In(As)Sb materials have high electron mobility and narrow band gap (approximately 78,000 cm2/Vs and 0.17 eV at room temperature) characteristics and are widely applied to a high speed Hall sensor and a long wavelength measuring device, they are attracting attention in various industrial fields. The importance, prior researches, and applications of an Sb based semiconductor are described in paper of B. R. Bennett [B. R. Bennett et al., Solid State Electronics vol. 49, pp. 1875, 2005].
An In(As)Sb layer can be manufactured by a liquid phase epitaxy (referred to as “LPE” hereinafter) method. However, the LPE method is an equilibrium growth method, which allows non-uniform mixing of materials. Thus, the LPE method is disadvantageous in that it requires high precision and depends on experiences of operators and performance of growth devices. Furthermore, since it is essentially difficult to control impurities and boundaries, only a few enterprises and research institutes are able to control the In(As)Sb layer based on unique experiences. Low quality In(As)Sb layer having a relatively low electron mobility (less than 20,000 cm2/Vs) is industrially produced by a sputtering method.
Meanwhile, because a molecular beam epitaxy (referred to as “MBE” hereinafter) method or a metal organic chemical vapor deposition (referred to as “MOCVD” hereinafter) method is a non-equilibrium growth method, which can overcome the non-uniform mixing phenomenon, they are gaining focus as substitute of the LPE method. However, so as to embody the MBE method and the MOCVD method, a high quality substrate is required. As shown in FIG. 1, which is a graph showing lattice constants and band gaps of group III-V compound semiconductors [B. R. Bennett et al., Solid State Electronics vol. 49, pp. 1875, 2005], a high quality substrate suitable for an In(As)Sb having a maximum lattice constant of 0.65 nm is commercially implausible. Thus, research on a method of growing In(As)Sb using GaAs (having a lattice constant of 0.565 nm) or Si (having a lattice constant of 0.543 nm), which are industrially easy to obtain and inexpensive, has been performed actively.
For example, a high quality InSb layer is prepared on a GaAs substrate by using a low temperature-high temperature processing method (LT-HT method) [Appl. Phys. Lett. vol. 84, pp. 4463, 2004 by T. Zhang et al.]. An InSb layer is grown on a GaAs substrate to have an intermediate layer of AlSb [Physica E vol. 21, pp. 615, 2004 by T. Sato, M. Akabori, S. Yamada]. Further, an InSb layer is successively grown on an Si, GaSb, or AlSb substrate [Appl. Phys. Lett. vol. 89, pp. 031919, 2006. by Y. H. Kim et al.].
According to the LT-HT method, a low quality InSb layer is grown at a temperature lower than an optimum growth temperature of an InSb layer in order to form the InSb layer on a GaAs substrate, and then the growth temperature of the InSb layer is increased to the optimum growth temperature, which leads to a formation of a high quality InSb layer.
FIG. 2 is a graph showing the thickness and the electron mobility of an InSb layer grown on a GaAs substrate by the LT-HT method, which is described in Physics E vol. 20, pp. 216, 2004 by T. Zhang et al. As shown in FIG. 2, in order to prepare an InSb layer having high electron mobility of 50,000 cm2/Vs by the LT-HT method, an InSb layer thicker than 3 um should be grown. Defects occur mainly at a lower portion of the InSb layer in the vicinity of the GaAs substrate due to the lattice constant difference (15%) between the GaAs substrate and the InSb layer. Accordingly, the thick InSb layer is formed to prevent the aforementioned defects. Consequently, the InSb layer is formed thickly to enhance the quality of an upper portion of the InSb layer. However, the thicker the InSb layer is formed, the longer manufacturing time is, thereby deteriorating the productivity.
And, in the process of forming the InSb layer, upon forming a lower layer of the InSb layer, the GaAs substrate has to be maintained at low temperature. Then, when forming an upper layer of the InSb layer, the GaAs substrate should be maintained at high temperature. This requires longer manufacturing time, which also leads to a reduction of the productivity.